docs: def set(self, *args):
          """
          Set the value of a single instance of this parameter.
  
          Args:
              args: value if the parameter is scalar, index and value
              otherwise.
  
          Raises:
              RuntimeError: If the entity has been deleted in the underlying
              AMPL.
  
              TypeError: If the parameter is not scalar and the index is not
              provided.
          """
          assert len(args) in (1, 2)
          if len(args) == 1:
              value = args[0]
              self._impl.set(value)
          else:
              index, value = args
              if isinstance(value, Real):
                  self._impl.setTplDbl(Tuple(index)._impl, value)
              elif isinstance(value, basestring):
                  self._impl.setTplStr(Tuple(index)._impl, value)
              else:
                  raise TypeError